Convert string of numbers to SSN format in PHP

string_to_ssn.php

// Format string to SSN (Social Security Number) in the format of XXX-XX-XXXX
function string_to_ssn( $ssn = "111223333" ) {
  return substr($ssn, 0, 3).'-'.substr($ssn, 3, 2).'-'.substr($ssn,5);
}

// Format string to SSN by preg_replace
function string_to_ssn_2( $ssn = "111223333" ) {
  $ssn = preg_replace('/[^\d]/', '', $ssn);
  $ssn = preg_replace('/^(\d{3})(\d{2})(\d{4})$/', '$1-$2-$3', $ssn);

  return($ssn);
}

what if it's an int?

convert it to a string first.